20 – Animals

01. Rest for Animals

Just as a Jew is commanded to rest on Shabbat, so too, he is commanded to allow his animals to rest. There are two commandments that address this issue, one positive (aseh), as the Torah states (Shemot 23:12): “Six days you shall do your work, but on the seventh day you shall cease, so that your ox and your donkey may rest, and the son of your maidservant and the stranger may be refreshed.” And one negative (lo ta’aseh), as the Torah states (Shemot 20:10): “But the seventh day is a Shabbat of the Lord your God; you shall not do any melakha – you, your son or daughter, your male or female slave, or your beast, or the stranger who is within your settlements.” The mitzva of allowing animals to rest is not one of the 39 melakhot but a mitzva in its own right; its violation is not punishable by death or lashes (Shabbat 154a; MT 20:1-2).

Even though the Torah in those verses mentions beasts, oxen, and donkeys, the prohibition applies to all animals, including birds and fish (MB 305:1). Therefore, one may not release carrier pigeons on Shabbat, and one may not use trained dolphins to pull a boat. The Torah specifies the ox and the donkey because they are the beasts of burden most commonly used for plowing and carrying heavy loads.

One who causes an animal carrying a load to move from one place to another on Shabbat, whether by striking, pulling, or ordering it, transgresses Torah law. This prohibition is referred to as Meĥamer. Even if the animal belongs to a non-Jew or is ownerless, one may not cause it to walk with a burden. If one causes his own animal to do so, then in addition to transgressing the lo ta’aseh against doing work, he has also violated the aseh of allowing animals to rest (SA 266:1-2; MB ad loc. 7-8). The latter commandment applies on Yom Kippur as well (there is disagreement about whether it applies on Yom Tov; see MB 246:19).

A Jew may not rent his animal to a non-Jew who will use it to do work like plowing or carrying burdens in the public domain on Shabbat. If a Jew rents out an animal with the understanding that it will be returned before Shabbat, but it is not, he should declare the animal ownerless before Shabbat to avoid violating Torah law (SA 246:3). If a Jew and a non-Jew are co-owners of an animal, the Jew may not permit the non-Jew to work the animal on Shabbat. However, if when they first bought the animal they specified that the non-Jew would be the sole owner on Shabbat, while the Jew would be the sole owner on a different day of the week, then the non-Jew may work the animal on Shabbat, because on Shabbat it is his alone (SA 246:5).

A Jew may allow a non-Jew to ride his horse or other animal on Shabbat, in accordance with the principle that “a living being carries itself” (he-ĥai nosei et atzmo). Therefore, the non-Jew who rides the animal is not considered a burden (nor are the clothes he wears, as they are secondary to his body). However, the Sages enacted that a Jew may not use an animal at all. He may not lean on it, place an object on it, or sit in a wagon hitched to it, even if a non-Jew is driving the wagon for his own purposes (SA 305:18). The reason for this enactment is to avoid burdening the animal on Shabbat (y. Beitza 5:2). Another reason is that while riding an animal, one may come to break off a tree branch in order to goad the animal, thus transgressing Kotzer (Beitza 36b).

A Jew may not take another Jew’s animal outside of teĥum Shabbat. This teĥum is based on the teĥum of the animal’s owner (see below, 30:3). If the owner entrusted the animal to a shepherd, whether Jew or non-Jew, the teĥum is based on that of the shepherd (SA 397:3-5). The prohibition is only for the animal to leave the teĥum at the initiative of its owner; it is not prohibited for the animal to leave of its own volition or for a non-Jewish shepherd to take it outside the teĥum (Rema 305:23; MB ad loc. 79).

02. Animals and Carrying

As we have seen, one must allow animals to rest on Shabbat. This includes making sure that one’s animal does not enter a semipublic (karmelit) or public domain with a burden on its back. However, not everything an animal carries is defined as a burden. Just as one may enter a different domain wearing his clothes because they are secondary to his body, so too a donkey suffering from the cold may be taken outside wearing a pack saddle that is meant to warm it. Other animals, though, which do not suffer from the cold, may not be taken outside with a saddle (SA 305:7). Similarly, a dog that is wrapped in an article of clothing may not be taken outside. Since it does not truly need this, the clothing is considered a burden. If one is not taking the dog outside, one may dress it, as there is no prohibition to carry in a private domain.

One may take out an animal that is wearing a bandage to protect an injury or a sheep that is wearing a cover designed to keep its wool from getting dirty. This is on condition that they are tightly bound to the animal, with no possibility that they will fall off, thus ensuring that no one will end up carrying them in a semipublic or public domain (SA 305:6). One may not take out an animal with a muzzle that is meant to prevent the animal from grazing in other people’s fields. This is because the muzzle is not worn for the animal’s sake, but for the sake of the fields’ owners (SA 305:11).

One may not lead an animal with a bell around its neck, as doing so generates sound, and it is rabbinically prohibited to generate sound with an object specifically designed for this purpose, such as a musical instrument. However, if the bell is silenced and makes no sound, the animal may be led around in a private domain but not a public domain. If the animal were to be led around in a public domain, it would seem like it was being taken to market for sale (Shabbat 53a and 54b; MB 305:42-43). The bell itself is not considered a burden as it is secondary to the animal’s halter.

One may take out a horse wearing a bridle or a donkey wearing a halter since these items are used to direct the animals and to prevent them from running away. However, a donkey may not be taken out wearing a bridle, as this would be an excessive precaution, far more than is necessary to ensure that the donkey will not run away. The general principle is that anything normally used to ensure that an animal will not run away is not considered a burden, but anything excessive is considered a burden (SA 305:1; MB ad loc. 8).

A dog may be allowed out in a public domain wearing its collar, because that is the normal way for it to go out since it allows one to restrain the dog if necessary by grabbing its collar or attaching a leash to it (SA 305:5; MB ad loc. 12). The person holding the leash is not considered carrying the leash, since it is secondary to the dog’s body. However, he must take care to grasp the leash within a tefaĥ of its end. He also must make sure that the leash does not droop to within a tefaĥ of the ground at any point. If either of these things happens, it looks like he is carrying the leash. If the leash is too long, he may wrap it around the dog’s neck so it is less likely to droop (SA 305:16).

A blind person may enter a public domain with a seeing-eye dog, even though he is holding the harness attached to the dog. Since the harness is always attached to the dog, it is secondary to its body, and there is no problem of carrying. (Although Orĥot Shabbat 31:17 is stringent, it seems reasonable to permit, as explained in Harĥavot; this is also the position of Mikveh Ha-mayim 4:39; Menuĥat Ahava 3:27:49; and Yalkut Yosef 305:59.)

A dog may be taken out into a public domain wearing dog tags connected to its collar or ear and on which is engraved the name of the dog’s owner. The tags make it clear that the dog has an owner, and thus people are more likely to leave it alone.[1]


[1]. AHS 305:5 forbids taking out a dog wearing dog tags as a sign for people to leave it alone. He brings a proof from the rule that forbids taking out roosters wearing strings as a similar sign to people (SA 305:17). However, SSK ch. 27 n. 34 cites R. Shlomo Zalman Auerbach as permitting it, since this sign is for the dog’s benefit and protection. In contrast, if the goal is simply to avoid paying a fine, the dog tags are prohibited. It would also seem that if the sign is permanently attached to the animal’s collar, then it is secondary to the collar and is not considered a burden, as explained in Tosafot, Shabbat 54b, s.v. “mishum”; MA 305:6; and Eliya Rabba.According to Rashi and Ran, one may take out a dog or other animal with a collar whose purpose is solely decorative, on condition that doing so is the common practice. Tosafot and Rabbeinu Yeruĥam maintain that if the collar does not serve a protective purpose, it is forbidden. Baĥ rules stringently (MA 305:1; MB ad loc. 12).

03. Feeding Animals

An animal may be led to graze in a grassy area, and it does not constitute Kotzer since the animal is eating for its own sake. We are not commanded to make sure that animals keep Shabbat, only that they do not labor for our benefit (Shabbat 122:1; SA 324:13).

One may provide food and water to animals in his possession that depend on him, like cows, chickens, and cats. Food and water may also be provided to animals belonging to another Jew. However, one may not feed or water self-sufficient animals like bees and doves. Even though feeding them is not a melakha, the Sages prohibited it because it is seen as requiring excessive effort (SA 324:11; BHL s.v. “ve-yonei”).

One may put food out for hungry animals like stray dogs and cats. As we know, God shows mercy to all His creatures, as it is written: “His mercy is upon all His works” (Tehilim 145:9). It is proper to emulate His ways (AHS 324:2-3; see MB ad loc. 31).

Animals are muktzeh. Therefore, they may not be picked up, nor may their limbs be lifted up. However, when it is necessary for their well-being (for example, in order to get them to their food), one may take hold of them and move their limbs to prevent them from suffering (tza’ar ba’alei ĥayim), as long as one does not lift them off the ground (SA 308:39-40; MB ad loc. 151).

If animals have difficulty eating unless the food is placed directly in their mouths, one may feed them in this way as long as he does not force-feed them. Force-feeding refers to shoving the food so far down their throats that they are unable to spit it up. This requires excessive effort (Shabbat 155b; SA 324:9-10).

One may ask a non-Jew to feed geese that have been force-fed for so long that they are unable to eat otherwise and would suffer hunger and pain if they were not fed on Shabbat. In such a case, one may ask a non-Jew to feed them one time on Shabbat. If there is no non-Jew available, the poskim disagree whether a Jew may feed them to minimize their suffering (MB 324:27). It is better not to force-feed geese at all, as doing so causes them pain and entails multiple prohibitions (see BHL ad loc.; SSK 27:26).

One may cut up food for animals if they would not be able to readily eat it otherwise. This includes cutting up pumpkins that are fed to animals and tough carcasses that are fed to dogs and that they have trouble eating. However, one may not cut up any food for them that they could eat by themselves. Even if cutting makes it easier for them to eat, it is excessive effort and thus forbidden on Shabbat (SA 324:3-8).

04. Milking on Shabbat

Torah law forbids milking a cow or any other animal on Shabbat, as doing so separates the milk from the cow’s body and constitutes Mefarek (separating something from its source), a tolada of Dash. Just as one may not separate grain from its husk, so too, one may not separate milk from its source (Shabbat 95a).

The problem is that if a dairy cow, which produces great quantities of milk, is not milked on Shabbat, it suffers greatly. Therefore, the Sages permitted asking a non-Jew to milk a cow on Shabbat. Even though, generally speaking, it is rabbinically prohibited to ask a non-Jew to do melakha for us on Shabbat, here they suspended the prohibition in order to avoid tza’ar ba’alei ĥayim. It is true that this milk is muktzeh on Shabbat. However, after Shabbat a Jew may drink or sell it (SA 305:20).

If there is no non-Jew available, a Jew may milk the cow, as long as the milk goes to waste. For example, it may be milked directly onto the ground, or into a bucket that contains an agent that will ruin the milk. This is because milking to make use of the milk is prohibited by Torah law, whereas milking for another reason, in which the milk goes to waste, is only rabbinically prohibited. A Torah prohibition may not be transgressed in order to prevent animals’ suffering, but the Sages suspended their own enactment.[2]

Nowadays, dairy farming has been modernized, and milking is automated. A cup is placed on the teat and connected to a pump via a tube. If there is a non-Jew available, one may ask him to turn on the machine and place the cups on the cow on Shabbat, because otherwise the cows would suffer. If no non-Jew is available, common practice is for a Jew to use a timer or a delay mechanism that is set before Shabbat to turn on the machine. On Shabbat, before the machine turns on, the cups are attached to the cow’s teats, and then the machine turns on and automatically pumps out the milk. Thus, the Jew has not performed any melakha directly, for when he attached the cups, the machine was not on. Even though placing the cups on the teats causes a melakha to take place, this is not prohibited by Torah law. The Torah only forbids direct action, as it states: “You shall not do any melakha” (Shemot 20:10). The Sages forbade indirectly causing a melakha to be performed. Here, to prevent the cows from becoming painfully engorged, the Sages permitted acting via grama. After Shabbat, a Jew may benefit from this milk.

If the cups must be attached to the teats while the machine is operating, then doing so in order to save the milk violates Torah law. Therefore, the milk should spill directly onto the ground, making the action rabbinically prohibited and thus permissible to prevent tza’ar ba’alei ĥayim (SSK 27:50; for the laws relevant to a woman who is engorged, see above 11:17).


[2]. Even though according to Ramban, milking is only prohibited rabbinically, halakha follows the opinion of Rif, Rambam, and Rashi that milking is prohibited by Torah law. On account of the animals’ suffering, the Sages permitted asking a non-Jew to milk on Shabbat (most poskim maintain that tza’ar ba’alei ĥayim is Torah law; see Peninei Halakha: Collected Essays Likutim III 10:6.) If no non-Jew is available, a Jew may milk the cows, but in such a way that the milk will go to waste, since according to Rabbeinu Tam (cited in Tosafot, Ketubot 6a) one may milk wastefully on Shabbat. Even though Ri (cited ad loc.) maintains that one may not milk in such a manner, in order to prevent animal suffering we permit it (SSK 27:49; Ĥazon Ish 56:4).

05. Carrying Pets and Sick Animals

As we will see later on (23:5), anything that has no practical use on Shabbat is muktzeh and may not be carried. Animals are included in this category and thus may not be carried on Shabbat. If, in order to prevent them from being hurt, it is necessary to move them, the Sages permitted pulling them but not picking them up (SA 308:39-40). At first glance, this would seem to pertain to house pets like cats and dogs, and indeed, this is the position of Yalkut Yosef (vol. 2, p. 383) and Orĥot Shabbat (19:124). However, it seems more reasonable to assume that muktzeh pertains only to animals with which one does not normally play. Pets whose owners play with them and pick them up all week long would not be muktzeh, and their owners may thus touch them and pick them up on Shabbat. Similarly, seeing-eye dogs are not muktzeh (Igrot Moshe, OĤ 5:22:21; Shulĥan Shlomo 308:74). Although some are stringent, muktzeh is a rabbinic prohibition so the halakha follows those who are lenient.[3]

A fish that jumped out of an aquarium and will presumably stay alive if it is returned may be put back even though it is muktzeh. This is because, when necessary, and when there is no other solution, one may move a muktzeh object to prevent tza’ar ba’alei ĥayim. Even though some are stringent in this case, one may rely on the lenient approach (See SA 305:19; MB ad loc. 70; SSK 27:28).

If a fish in an aquarium dies, and it is possible that if it is left in the aquarium other fish will catch whatever terminal disease it had, then even though the dead fish is muktzeh, it may be removed from the tank to save the remaining fish. If there is a dog or cat in the vicinity, the fish should be fed to them (see SSK 27:29).


[3]. Maharaĥ Or Zaru’a §81 permits carrying pet birds in their cage, maintaining that they are not muktzeh, albeit while noting that Rosh disagrees and maintains that all animals are muktzeh. Indeed, this is the opinion of the majority of poskim according to MB 308:146 and SSK 27:27 (Yabi’a Omer 5:26 states that if one wishes to move birds in order to prevent their suffering, such as if the sun is beating down on them, one may rely on Maharaĥ Or Zaru’a). However, all these discussions relate to birds, which are not commonly carried. In contrast, today people keep house pets and carry them around all week. For this reason, Igrot Moshe states that birds are muktzeh (OĤ 4:16) and succinctly that pets are not (OĤ 5:22:21). This is also the position of R. Shlomo Zalman Auerbach in Shulĥan Shlomo 308:74. Others are stringent (Yalkut Yosef vol. 2, p. 383; Orĥot Shabbat 19:124). As I have written above, the halakha follows those who are lenient. Bird cages and aquariums, which are not normally carried, are muktzeh. If one normally moves them around during the week for decorative purposes, then according to R. Shlomo Zalman Auerbach they are not muktzeh (Shulĥan Shlomo 308:74:2).

06. The Melakha of Tzad

Trapping animals was one of the melakhot performed for the Mishkan. They would trap teĥashim to make curtains from their skins and the ĥilazon to produce tekhelet to dye the curtains (Shabbat 73a; Rashi ad loc.; Shabbat 75a).

The Torah prohibition of Tzad is limited to those animals – beasts, birds, or fish – that are normally trapped or hunted for a purpose, whether to eat their meat, use their skins, or enjoy their beauty (as is the case with parrots). In contrast, one who traps species that are not normally hunted, such as flies and other insects, violates rabbinic law (Shabbat 106b; SA 316:3).

The prohibition of Tzad does not apply to tame animals that do not run away from their owners, such as cows, donkeys, and dogs. Since in any case they stay with their owners, there is no such thing as trapping them (Rema 316:12; MB ad loc. 59). Nevertheless, carrying these animals is prohibited, as they are muktzeh. When necessary they may be grabbed and dragged into their pen or kennel, as long as they are not picked up (SA 308:40; see section 3 above).

If an animal is partially tame in that it runs away when a human tries to grab it but returns to its cage at night, its trapping is rabbinically prohibited (Rema 316:12: MB ad loc. 57, 59). When necessary, in order to avoid monetary loss or tza’ar ba’alei ĥayim, one may rely on those who are lenient and trap a partially tame animal. (See SA ad loc.; SSK 27:36.)

The Torah prohibition refers to completely trapping an animal; that is, holding it in hand, with ropes, or in a cage such that one can do with it as he pleases. Similarly, one who shepherds an animal into an area small enough that he can chase and catch it in one motion, he violates Torah law. In contrast, if one herds an animal into a large area where he would still need to chase it down in order to capture it, he does not violate Torah law, as the animal is not well and truly trapped. However, this is rabbinically prohibited, because the animal can now be more easily trapped. If he subsequently captures it, even though doing so is easier than usual, he is still violates Torah law, as this is the Tzad that the Torah forbids (Shabbat 106b; SA 316:1).

Hunting with the aid of a dog is forbidden. However, if one commands the dog with his voice and does not actually touch it, the prohibition is rabbinic. If he takes any action to help with the capture, he violates Torah law (Rema 316:2; MB ad loc. 10).

A mouse trap may be put out on Friday, since no action is taken on Shabbat. However, it is rabbinically prohibited to put out a trap on Shabbat. This is not prohibited by Torah law, as it is not certain that the trap will succeed in catching anything (MB 316:18).

An animal may be freed from a trap on Shabbat. While there is a prohibition to trap an animal, there is no prohibition to free an animal from a trap on Shabbat (MB 316:25).

One who wishes to feed a caged animal or bird whose nature is to try to escape must take care not to open the cage even briefly. If he mistakenly opened the cage, then if the cage is so small that confining the animal or bird to it would be considered Tzad by Torah law, then the cage may not be closed even be-di’avad. If the cage is large enough that confining the animal or bird to it would only be rabbinically prohibited, be-di’avad one may close it, since the animal or bird was inside when Shabbat began (Pri Megadim; BHL 316:6 s.v. “ve-halakh”).

07. Unintentional Trapping

Just as one may not chase an animal in order to trap it, so too one may not exploit the opportunity to catch an animal that got stuck in a confined space. Therefore, if a deer enters a house, the door may not be closed behind it. If a bird flies in through a window, the window may not be shut behind it (Shabbat 106b; SA 316:5). If one wishes to close the door or window in order to protect against thieves or the cold, the animal must first be chased out of the house.

If the household members are having trouble chasing out the animal or bird because it is hiding and eluding pursuit, if necessary the door or window may be closed. This is because the person doing so does not intend to trap the animal or bird, but only to protect the house from thieves or the cold. Besides, even after the door or window is closed, the animal is not truly trapped, because capturing it is still an effort.

Similarly, if a window screen has flies on it, and one wishes to close the window beyond it in order to prevent the heat or cold from entering, he must first chase away the flies so that they are not trapped between the window and the screen. If it is difficult to do so, the window may be closed even while they are still there, since one does not intend to trap the flies, only to protect against the heat or cold. Besides, the flies are not truly trapped; even if he wants to catch them, he would have to make an effort to do so.

Similarly, one who wants to close a small box that has flies in it should chase them away before closing it. If it is difficult to chase them all away, he should leave something between the cover and the box in order to create an escape hatch for the flies. If necessary, the box may be closed even though a fly will be trapped inside it, since his intention is not to trap the fly, but only to close the box. Besides, the fly is not truly trapped; even if he wants to catch it, when he opens the box it may very well escape.[4]


[4]. In order to explain this halakha, we must first point out that in all the cases mentioned here, the trapping involved is only rabbinically prohibited, for the following reasons:1) The area is large enough that the animals are not truly trapped there. (If the box is very small, then Sefer Ha-Teruma maintains that the flies are considered trapped, while Tur maintains that they are not trapped since they can escape when the box is opened.)

2) Flies and the like are not species that are hunted. Thus doing so is only rabbinically prohibited

3) Since the goal is to close the house or box and not to trap anything, this is a melakha she-eina tzerikha le-gufah, which according to most poskim is only rabbinically prohibited.

In all the cases mentioned above, the intention is not to trap but simply to close the window. As a result, these are examples of psik reisha de-lo niĥa lei in cases of a double rabbinic prohibition. It is generally agreed that in such instances, one can be lenient when necessary. In cases of true necessity, we are lenient for a psik reisha even if there is only one rabbinic prohibition (as explained above in ch. 9 n. 2; see MB 316:15, SHT ad loc. 18, and the upcoming footnote). Accordingly, Ĥayei Adam 30:2 and MB 316:5 state that if a bird flies into a house and is located in an area large enough that trapping the bird would only be rabbinically prohibited, one may close a window or door on account of the cold. Additionally, one may bring into consideration the following opinion of Rashba (Shabbat 107a) based on the Yerushalmi. Even though the Sages state: “If a deer enters a house and one locks it in, he is liable” (Shabbat 106b), nevertheless Rashba writes that as long as his intention in closing the door is to protect the house, it is not prohibited. Even though we do not follow this Rashba, we can combine his opinion with other mitigating factors to support leniency. See Harĥavot.

08. Slaughtering (Shoĥet)

Shoĥet refers to the melakha of taking the life of a living being. For the Mishkan, they slaughtered teĥashim and goats in order to use their skins for the curtains (Shabbat 73a, 75a).

It is not only slaughtering that is prohibited. Rather, killing a living being in any fashion is forbidden by Torah law. It does not matter whether death is brought about by striking, strangling, or any other method. One who kills a tiny ant violates Torah law, as does one who removes a fish from water, since this kills the fish. Similarly, one who reaches his hand into an animal’s womb and aborts its fetus on Shabbat violates Torah law (Shabbat 107b).

The Torah prohibition applies when the animal is killed for its corpse, i.e., to make use of its meat, skin, or blood. In contrast, one who kills destructively, such as stamping on ants because he wants them dead, transgresses rabbinically.

If one is walking and comes across ants, he should jump over them in order to avoid killing them and violating a rabbinic prohibition. If there is a colony of ants in his path and it is impossible to step there without killing ants, he should walk around them. If he is in a place where he cannot pass without walking on them, he may continue walking, since he does not intend to kill them. It is preferable that he walk on the sides of his feet and do his best to avoid killing ants.

Similarly, if there are insects in a toilet and there is a reasonable chance that flushing the toilet will kill them, it is preferable, when possible, to wait until they fly or crawl away. However, if they do not emerge, or if one must flush for the sake of human dignity, he may do so.

If ants are in a sink and can be blown out of the way, that is best. If it is difficult to do so, dishes or hands may still be washed, even though this will probably drown the ants. Since the one washing is not interested in killing them, and he needs the water, it is not prohibited.[5]


[5]. Even if it is clear that the ants or other insects will be killed, it is a psik reisha de-lo niĥa lei in a case of a double rabbinic prohibition, as the act is destructive and is being done with a shinui. We saw above (ch. 9 n. 2) that when necessary we are lenient in such cases. Even if one insists that the killing here is not done with a shinui, it is still a case of psik reisha de-lo niĥa lei applying to a rabbinic prohibition. In cases of true necessity, we are lenient even in such a case (MB 316:5; SHT 321:68, 337:10). Some maintain that we may be lenient in such a case even le-khatĥila (Yeĥaveh Da’at 2:46). If one walks on the sides of his feet, then the killing is definitely done with a shinui. Besides, it is possible that this will not kill them. Even though Menuĥat Ahava 3:18:10 and Orĥot Shabbat 14:27 are stringent, the primary position is the lenient one, as is recorded in Minĥat Ish 19:9. For a toilet infested with gnats, Minĥat Yitzĥak 10:27 offers additional factors to permit flushing: human dignity, grama, melakha she-eina tzerikha le-gufah, and maybe even mitasek. Shevet HaLevi 6:94 is in agreement.Killing lice: Shabbat 12a records a disagreement about killing lice on Shabbat. The conclusion reached there is that killing them involves no prohibition, as they spontaneously generate from inanimate matter. Now, however, since we know that lice do reproduce, it is forbidden to kill them. Halakha is determined in accordance with current knowledge. See Harĥavot.

09. Wounding (Ĥovel)

Just as it is prohibited by Torah law to kill any living being, it is also prohibited by Torah law to cause a loss of blood. After all, “blood is life” (Devarim 12:23). Additionally, with the release of a little blood, there is a localized loss of life. This prohibition applies even when the blood does not exit the body, but simply hemorrhages from blood vessels and accumulates under the skin. This too is viewed as a localized loss of life (SA 316:8; BHL s.v. “ve-haĥovel).[6]

Accordingly, if one strikes another person on Shabbat with intent to injure and causes a hemorrhage or hematoma, he is not only guilty of an interpersonal transgression but also desecrates Shabbat. This is also true of one who angrily strikes an animal and causes a hemorrhage or hematoma. In addition to violating tza’ar ba’alei ĥayim, he transgresses the prohibition of Ĥovel.

One may not do a blood test on Shabbat. Since the goal is to use the blood, taking it is prohibited by Torah law. In cases of danger to life, of course, it is permitted. It is also forbidden to scratch or pick at a scab if doing so will cause it to bleed, or to brush one’s teeth in a way that will cause the gums to bleed (as explained in 14:2).

A Jew may administer a shot to one who is ill, even if not dangerously so, as long as the injection is into flesh, since this will not necessarily cause the sick person to bleed. In contrast, if the shot or infusion is done into a vein, it is prohibited for a Jew to administer it to one who is not dangerously ill, since there will definitely be at least a little blood. However, a non-Jew may be asked to give this injection. If the sick person is dangerously ill, even a Jew may give the injection (below 28:7).


[6]. Rashi maintains that Ĥovel is a tolada of Shoĥet. Several other Rishonim (such as Ran) discuss the issue but do not make it clear whether Ĥovel is a tolada of Shoĥet or part of the av melakha. Rambam maintains that Ĥovel is liable because of Mefarek, a tolada of Dash.

10. Trapping and Killing Snakes, Scorpions, Mosquitoes, and Other Pests

Danger to life overrides Shabbat. Therefore, animals likely to endanger human life may be killed even on Shabbat, like poisonous snakes and scorpions. Even if one is unsure whether a particular animal is poisonous, he may kill it. Similarly, a dangerous dog or rabid animal may be killed.

It is prohibited on Shabbat to kill animals whose bites hurt a great deal but are not life-threatening. This applies to snakes and scorpions that are definitely not poisonous. It is only forbidden to kill them the way one would kill them during the week, so one may kill them in the course of walking; one walks in their direction and in the course of walking steps on them and kills them. The reason for this dispensation is that killing an animal in a destructive manner, when one does not have any use for the cadaver, is only prohibited rabbinically. Thus, in order to avoid great suffering, the Sages permitted killing such animals in the course of walking. However, it is prohibited to kill them directly, out of concern that people will conclude that one may kill animals even when there is no concern that they will cause harm. If such animals are chasing a person, they may be killed even without a shinui.

Even if they are not chasing anyone, a receptacle may be placed over them in order to neutralize the threat. This does not need to be done with a shinui, because the person’s goal is not to trap them, only to prevent them from stinging or biting (SA 316:7; MB ad loc. 27).

Animals whose stings are not so painful, such as mosquitoes and fleas, may not be killed in any manner on Shabbat. If the mosquito or flea is clinging to one’s skin and cannot be removed without being grabbed, the Sages permitted grabbing it in order to remove it. This is on condition that he not kill it or even squeeze it, which might kill it. Even though grabbing an animal without intending to use it is rabbinically prohibited, the Sages were lenient here since the goal is to avoid suffering (SA 316:9). If one wishes to grab a flea and remove it from under his clothing rather than from his skin need not be dissuaded from doing so (MB 316:37; SHT ad loc. 63).

If there are mosquitoes or other pests in a room, one may spray insecticide to repel them as long as he does not spray the bugs directly and leaves open a window through which they can escape. This way he will not necessarily kill any of them. However, one may not spray them directly or to spray in a place where they have no means of escape, because then he will definitely kill them and transgress a prohibition (Yabi’a Omer 3:20; see SSK 25:6).

One may apply liquid mosquito repellent on Shabbat, but not an ointment (see above, 14:5).

One may place tablets into a plug-in device that contains a heating element that causes the tablets to heat up and release a mosquito-repellent vapor. It is proper to place the tablets at a short distance from the heating element so that they do not reach the temperature of yad soledet bo, which might present a problem of Bishul (Ha-ĥashmal Ba-halakha vol. 2, p. 364; above 10:4). However, if one is uncertain whether the tablets will reach yad soledet bo, he may place them.